Refrigeration



E. A. WEAVER Jan. 3, 1933.

REFRIGERATION Original Filed Nov. 9, 1929 8 Sheets-Sheet 0 5 fl gm I a iv :3 WW m w 6 l\ 0 j fnvenfor. I Easim r A. by

E. A. WEAVER REFRIGERATION Jan. 3, 1933.

Original Filed Nov. 9, 1929 8 Sheets- Sheet 2 Jan. 3, 1933. W AVE 1,892,821

REFRIGERATION Original Filed Nov. 9, 1929 8 Sheets-Sheet 3 In men for Easim an A, Ma er OJ WMX A *liyk Jan. 3, 1933.

E. A. WEAVER REFRIGERATION 8 Sheets-Sheet 4 Original Filed Nov. 9, 1929 fnven'lor EasZmanA.Weav r by ,M IWV Afiyf Jan. 3, 1933. I 5, WEAVER 1,892,821

REFRIGERATION Original Filed Nov. 9, 1929 8 Sheets-Sheet 5 u i i i [72 main r EasimanA.We W av/r Al'lj s.

Jan. 3, 1933.

E. A. WEAVER REFRIGERATION Original Filed Nov.

9, 1929 8 Sheets-Sheet 6 Inventor Eastman A. e e.

b waaw/Z A't'tys.

Jan. 3, 1933. E, WEAVER 1,892,821

REFRIGERATION Original Filed Nov. 9, 1929 8 Sheets-Sheet 7 Inoen for AQW A iii s.

Jan. 3, 1933.

E. A. WEAVER REFRIGERATION Original Filed Nov. 9, 1929 8 Sheets$heet 8 Easfman A.Weav 1: byw w wltf Twq Patented Jan. 3, 1933 UNITED STATES PATENT OFFICE EASTMAN A. WEAVEB, OF WINCHESTER, MASSACHUSETTS, ASSIGNOB, BY MESNE ASSIGNMENTS, TO STATOR REFRIGERATION, INC., A CORPORATION OF DELAWARE REFRIGERATION Application filed November 9, 1929, Serial No. 405,948. Renewed September 23, 1932.

filed January 7, and April 13, 1928,'re-- p y, close apparatus of this general character'in which' the propellant is effective in pumping the, refrigerant in a plurality of stages, thereby increasing the operating efficiency of the system, while the last-identified application also discloses such a system in conjunction with a cooler which may be disposed above the other component elements of the apparatus; thus, for example, this system may be employed in an installation where the cooler is'located in one story and the remain der of the system in a lower story, as for example in the basement, means being provided to pump the condensed refrigerant from the lower story to the cooler. The present invention affords a system of the same general character which may either be provided with a single stage pumping means of the character disclosed in the above-identified appli-.

' cation of EastmamA. Weaver or a multi-stage pumping arrangement of'thecharacter provided in other applications referred to and which may also include'a refrigerant lifter of the type disclosed in application Serial No.

In accordance with the present invention,

' means are provided to permit the apparatus to be more compact and/or to have 'ahigher boiler pressure and/or better heat efiiciency than has heretafore been feasible with systems of this character. For this purpose a propellant lifter preferably is arranged to receive the condensed propellant after it has given up its energy in causing the circulation of the refrigerant and to lift it to a region above the pumping means and/or the propellant condenser, a suitable return pipe being provided to contain a column of the propellant which balances the boiler pressure and through which the liquid returns to the boiler.

For this purpose a duct may be provided to permit a little of a fluid such as refrigerant vapor to pass from a higher to a lower pressure portion of the system, and in the course of its passage upward through a small tube, to entrain liquid propellant and lift the same to a higher level. Preferably this small tube is in heat transfer relation to the heating factor forthe boiler of the same, so that the circulating fluid may be maintained vaporized in response to the-heat to which it. is subjected. In this manner a small part of one of the Working fluids of the system, such as the refrigerant, is vaporized at relatively high pressure so that it has sufficient energy to lift the propellant to the desired level. Preferably suitable means are associated with this lifter to permit the ready separa-' tion of this vaporized refrigerant from the lifted propellant. Furthermore, a measuring or divid ngfactor is preferably employed to separate one portion of the lifted propellant from another portion thereof so that part of the propellant may be returned. directly to the vaporizer and so that the potential energy of another part, of the lifted propellant may be emploved in an auxiliary pumping circuit or circuit Thus. for example, the propel ant may be' used effectively in providing the energy required to lift the condensed refrigerant to a cooler at a level above the remainderof the system, this portion of the apparatus in general resembling that disclosed in copending application cation Serial No. 269,712 referred to above. Th 3 present invention is advantageous, however, in providing an arrangement that permits the operation of the purger and water lifting means by a single stream of propellant, thereby providing .an arrangement of wide adaptability. Thus, the lifted propellant may be employed to raise the refrigerant to the desired level after it has been effective in causing the exhaustion of noncondensable gases from the system, or in other words, the purger and the refrigerant lifter may be arranged in series.

This invention provides a refrigerating system of the character indicated in which the various pipes, ducts, condensers, and other component elements are compactly arranged so that the major portion of the same may readilybe installed in a single com-' partment or container, and so that the minimum number of connections are required for the satisfactory operation of the system. This apparatus is also arranged to prevent the accidental development of excess pressures, due for example to the clogging of the aspirator nozzles.

The present invention in its preferred emhodiment also aflords an arrangement particularly determining the preferred course of the liquids along parallel parts of the circuits when the system is started. Thus, for example, under these conditions, the immediate d version of propellant to the refrigerant l fter is effected, which in turn causes the immediate diversion of some of the refrigerant to the propellant lifter.

In the accompanying drawings which provide a concrete exemplification of the invention:

Fig. 1 is a side elevational view, more or less diagrammatic in character with certain supporting members omitted, showing the entire system with the exception of the cooler and the adjoining parts;

Fig. 2 is an end elevational view of the assembly shown in Fig. 1;

Fig. 3 is a top view of the upper part of this assembly;

Fig. 4 is an elevational view, more or less diagrammatic in character, showing the arrangement of the cooler and related piping;

Fig. 5 is a side view of the refrigerant condenser;

- Fig. 6 is an end elevation of the same, parts being broken away for clarity of illustration;

Fig. 7 is a top view of the condenser; Fig. 8 is a view, partly in section and partly in elevation, of a portion of the auxiliary vaporizing means which forms apart of thepropellant lifter, also illustrating related parts; r

Fig. 9 is a section on line 9. 9of Fig. 8; Fig. 10 is an elevational view of one stage of the umpin means for the system, certain related pipes being shown, and parts being broken away for clarity of illustration;

Fig. 11 is a vertical sectional view of the measuring factor that is associated with the propellant lifter and the propellant return p 12 is a perspective view of one of the elements of the assembly illustrated in Fig. 11;

Fig. 13 is a section on line 13-13 of Fig. 11;

Fig. 14: is a sectional detail of a part of the purger assembly;

Fig. 15 \is an elevational detail of this portion of the system;

Fig. 16 is a side elevational view of the vaporizer and the ducts connecting the same to the aspirator nozzles, parts bein shown in section and indicated in dot and ash lines;

Fig. 17 is an end elevation of the assembly shown in Fig. 16, parts being broken away for clarity of illustration;

Figs. 18 and 19 are elevational views of the piping of upper part of the assembly, certain related parts being indicated by dot and dash lines;

Fig. 20 is a view partly. in section and partly in elevation of an aspirator assembly;

Fig. 21 is a sectional detail view of a portion of the pipes and related parts which are associated with the refrigerant lifting means; and

Fig. 22 is a sectional detail of a ortion of the means arranged to subject t e condensed refrigerant to a comparatively high li uid head.

n accordance with the present invention, a propellent fluid may flow about a propellant circuit, whilea lighter and more volatile refrigerant may flow about a refrigerant cirouit which has a part or parts in common with the propellant circuit. In the common part gr parts of the circuits vaporized ro el ant ma ive up its energy in umpihg the refrig ra nt, which also is in its Vapor phase. Preferably separate refrigerant and propellant condensers are provided in the propellant and refrigerant circuits. A suitable cooler is arranged in\the refrigerant circuit and m y e conveniently disposed at a level considerably higher than the common parts of the-circuits and the propellant condenser. In the case of a multi-stage system, the propellant circuit preferably includes parallel portions where energy is imparted from the propellent vapor to successive ortions of the refrigerant stream. Whi e a system of this general character may be emacter it is only necesary to emplo two liquids, not only in the main circuits of the system, but in allof the auxiliary circuits thereof, .such as the propellant ant lifters and the purger.

In the accompanying drawings, the numetal 1. designates a boiler or vaporizer which may conveniently be associated with a heating factor 2, such as a fire-box that in- .10 cludes a fuel burner which may be supplied by a duct 3 (Fig. 2) with suitable combustible fluid suchas ordinary illuminating gas. The upwardly extending flue 52 permits the ready exhaustion of the gases of combustion from the factor 2. An outlet pipe 4 is connected to the boiler 1 and has upwardly extending branches'6 that include flexibleor expansible-contractible elements 7 such as metal bellows (Figs. 16 and 17) j The flexible elements 7 permit the expansion and contraction of the parts adjoining the boiler to occur without throwing an undue strain upon aspirator nozzles 9 and 9. Preferably these 'noz'zles may be formed of comparatively thin material which is a relatively poor conductor. of heat, such as a nichrome alloy, and may form .the sole direct connections between the ducts 6, which normally contain hot propellent vapor, and the adjoining portions of the system which preferably are maintained at a lower temperature; Ducts 6 include frusto conical portions 209 containing. frusto-conical screens 201 which are adapted to prevent the passage of foreign particles to the aspirator nozzles. The lower parts of these screens 201 may be connected to thimble-like shells 203, each of which contains a central partition 204 with its lower edge spaced somewhat from the bottom of the shell. Preferably each duct 6 is inclined slightly and an opening 200 is provided in each shell 203 adjoining its upper side as determined by the inclination of the duct in which it is located. A suitable closure plate 210 is disposed above the space adjoining the opening 200 so that the shell element provides a trap for thecollection of condensed propellant, which may pass. about the lower edge of the central partition and out of the opening 200, thus returning to the boiler. This arrangement per mits condensed propellant to return to the boiler without necessitating its passage ,through the relatively finely meshed screen.-

eleinents 201, which would afiord a comparatively high resistance to the flow of the liquid propellant. I It is evident that propellant such as mer and then passes upwardly through. ducts 6 p 'to the aspirator nozzles 9 and 9. The nozzles preferably project into suitable mixing chambers 10 and 10 which are'adapted to receive refrigerant vapor. Figs. 10 and 20. For this purpose the mixing chamber 10 is and refriger cury is heated in the boiler 1 and vaporized nozzle. 9 at high velocity entrains refrigerant vapor in the mixing chamber 10 and thus causes evaporation of the refrigerant from the liquid in the cooler.

The mixture of propellent and refri rant vapors passes from the mixing cham r 10 to funnel 15 which is aligned with nozzle 9. Figs. 10'and 20 illustrate-more specifically this portion of the apparatus, the funnel having a portion of restricted diameter spaced from the mixing chamber and having a general downward inclination. Suitable cooling means such as fins 16 are associated with the funnel to efiect the condensation of the pro: pellentvapor at its comparatively high temperature of liquefication, as the energy'of the same is exhausted in aspirating and com pressing the refrigerant vapor. Since the temperature of the funnel 15 is wellabove the temperature of condensation of the refrigerant vapor at the pressure conditions revailingin this part of the system, the rerigerant vapor passes out of the funnel.

through the upwardly extending duct 20, a continuation of which is connected to the second stage mixing chamber 10. The propellent vapor in this mixing chamber is cf fective in further compressing the refrigerant and pumping the same into the funnel15 which is aligned with nozzle 9-. Ingeneral the nozzles, mixing chambers, and funnels for the two stages may be similar, but preferably the mixing chamber for the second stage pumping means is so arranged that the a funnel 15? is spaced at a somewhat shorter distance from the nozzle 9 than is the case with the first stage aspirator assembly.

Suitable drains are provided to remove the condensed propellant from the mixing chambers and condenser and compressor funnel. Thus, for example, the drains 21 and 21" may be connected to the lower portions of the mixing chambers to receive any particles of propellant which may'condense in this portion of the apparatus, while the drains 22 and 22 may be connected to thelower portions of the inclined funnels to collect condensed ropellant from the same and from the, ad oining refrigerant vapor ducts.- A refrigerant-vapor pipe 26 from the second stage fimnel 15" preferably extendsupwardly into a refrigerant condenser which is designated in general by the numeral 30.'

Figs. 5, 6 and 7 illustrate this condenser more in detail. It comprises a transverse header 31 which connects two condenser secs 'tions 32 and 33. Preferably't-heheader is have a gradual inclination downwardly from v the header 31 to a second header 36 that forms the lowermost portion of the condenser. The larger condenser section 32 preferably comprises a plurality of ducts 39 which have a gradual upward inclination from the header 31 to an upper header 40. The vapor pipe 26 may project upwardly into the intermediate portion of header 31, as shown.

The drains 21, 21, 22 and 22 are all connected to a common propellant collecting pipe 50 which inclines upwardly toward the boiler 1 and has an upwardly extending continuation 51 juxtaposed to the flue 52 that serves to provide a draft and an outlet for the gases of combustion that are emitted from the firebox 2.

A tube 60 of restricted diameter may be arranged to receive liquid from the header 36 of condenser 30, thus being adapted to drain condensed refrigerant from all parts of the same.

Preferably, as shown in greater detail in Fig. 22, the upper end of tube 60 opens into a chamber 59 which is provided with a cylindrical screen 58 surrounding the open end of tube 60 to prevent the entrance of foreign particles into the same. A short pipe 59 connects the chamber 59 with the condenser. Means which will be described below is provided to supply propellant to chamber 59 and the upper end of the tube 60; the latter has a restricted diameter so that successive bodies of propellant may pass down the same in the form of successive liquid pistons entraining bodies of the condensed refrigerant therebetween. The lower end of tube 60 is connected to a separating chamber 64 at the upper end of one leg of a trap 61, and the lower end of an upwardly extending pipe 63 issconnected to this chamber. Thus the heavier propellant tends to pass to the trap 61 and the lower part of the separating chamber, while the lighter refrigerant rises through the open upper end of pipe 63 into the chamber 65. A downwardly extending pipe 66 also has an open upper end disposed in chamber 65, and its lower end extends downwardly into a connecting duct 70. The chamber is also joined to the upper end of an inclined vaporizer duct 80 which presently will be described.

Duct receives a leg of the trap 61 so that propellant from the separating chamber 64 tends to overflow into the passage 70. The latter also receives the upper end of one leg of a trap 73, the opposite leg of which is extended to provide a substantially vertically disposed duct which is connected to an inclined pipe 76 the latter in turn is connected to drain 22 below its juncture with the corresponding compression funnel.

A pipe 72 extends upwardly to the level of the cooler and has a portion 72 of comparatively large diameter that is connected to the upper part of one end of chamber 70.

A chamber 72 is disposed at the upper end of the enlarged portion 72 of the duct 72. The propellant from trap 61 overflowing into chamber 70 passes into trap 7 3 and pipe 75 through connection 76 to drain 22. The height of this connection substantially determines the height of the propellant column which imposes its pressure upon the trap 73 and accordingly is substantially effective in determining the pressure conditions to which the chamber 70 and related parts of the system are subjected.

The major portion of the refrigerant which has been received from pipe 63 by chamber 65 returns through duct 66 to the chamber 70, a small portion of'this refrigerant passing to the secondary vaporizer 80. The refrigerant obviously tends to rise to the upper part of the connecting duct 70 and rises in pipe 72 from which it is returned to the cooler. Due to the enlarged diameter of the lower portion of pipe 72 and due to the chamber 72" provided in the same, there is no danger of propellant collecting in pipe 72 to the exclusion of refrigerant and preventing the desired formation of a column of the lighter liquid in pipe 72.

The heavy propellant bodies passing downwardly in pi e 60 impose such a pressure upon the liquld in trap 61 and through the connection 70 upon the liquid in trap 73 that the light refrigerant in pipe 72 is raised to the level of the cooler. Duct 70 is efiective only in permitting refrigerant which has passed upwardly through pipe 63 to chamber 65 and from the latter through pipe 66 to pass into pipe 72 and thus to be returned to the cooler, but this connection also permits the propellant in trap 61 to pass over into trap 73, filling leg 75 of this trap and extending up to the connection of pipe 76 with the drain 22.

Fig. 4 shows in detail the arrangement of the cooler, which comprises a receptacle 12- partially filled with liquid refrigerant, the connection 11* of the vapor pipe 11 being joined to the upper portion of this receptacle. The pipe 72 is connected'to a substantially upright duct 220, the 'upper end of which is connected through a by-pass 221 with the vapor pipe 11 and the open lower end of which is disposed within a chamber 223. The upper portion of the latter is connected by a pipe 224 with the lower part of the receptacle 12, while a pipe 226 connects th bottom of this receptacle with the lower part of chamber 223. Pipe229 having a U-shapcd trap norti on 230 connects the bottom of chamber 223 with the upright portion of pipe 11.

A suitable body of heavy liquid, such as the propellant, may be disposed in the lower part ofchamber 223 as well as in trap 230 and in the portion of pipe 226 which is connected to the chamber. The refrigerant liftedthrough rise through pipe 224 to receptacle 12. Propellant which accidentally strays into the cooler or pipe 220 passes to the bottom of the chamber 223, thus increasing the pressure in trap 230'. If suflicient propellant thus collects in the chamber, the mercury in the remote leg of trap 229 will riseto the juncture of pipes 229 and thus overflow into the latter and pass downwardly through the same to the propellant circuit. Thus means are provided automatically to effect the return of excess propellant from the cooler and the connected piping, while permitting the ready return of condensed refrigerant to the cooler.

Fig. 8 illustrates in greater detail the arrangement of the secondary vaporizer 80 and related parts. A duct 81 having a general downward inclination is connected to the chamber 65 and is adapted to receive liquid therefrom. A suitable by-pass or propellant return 83 is connected to this duct and to pipe 63. The duct 81 contains a body of closely packed porous material such as asbestos, which is designated by numeral 85. This porous material forms a suitable resistahce element through which. a small portion of the liquid from chamber 65 may seep. A screen 84 extends across duct 81 to prevent foreignparticles from clogging the pores of plug 85; and a cylindrical element 86 formed of meshed screening is disposed in the end of duct 81 to hold the plug in place. The end of duct 81 is juxtaposed to flue 52 and the former is accordingly maintained at a comparatively high temperature during I normal operation of the'system. This portion of duct 81 has a downward extension 87 which receives the upper end of a duct 90. The trap '83 is so disposed in relation to the porous plug 85 that propellant is prevented from clogging the same and is drained back to the trap 61 at the lower part of the system... Refrigerant vapor from plug 85 passes downwardly through tube 90, which is juxtaposed to the flue 52, to the lower end ofthe pipe 51.

The'plug 85 is subjected to a substantial pressure differential; in other words, the

pressure at its upper end adjoining the screen 84 is higher than that adjoining the pipe 90;

this pressure differential-cooperates with the heat from the flue 52 causing the vaporization of the refrigerant as it passes through the plug.

Pipe 51 is of restricted diameter so that vapor from the factor 80brea-ks 03 bodies of propellant'from the propellant column contained in thelower end of that pipe and lifts the same to the substantially vertical pipe 95 disposed at the upper part of the system. The upper part of pipe 95 has a downwardly extending continuation 96 that is connected to the upper part of the condenser 30,

i. e., to the header 40, while the lower end of pipe 95 forms one leg of a trap 98 (Figs; 18 and 19), the opposite leg of which is provided with a substantially horizontal continuation 99 that is connected to the measuring factor Figs. 11, 12 and 13 illustrate in greater detail the arrangement of the measuring factor 100 which comprises an outer tubular casing 101, the pipe 99 being connected to the upper end of this casing and adapted to vent fluid into the same. This fluid from pipe 99 flows into the annular space provided between tube 102 and the upper end of a sleeve 114 which is fitted within the casing 101, the top of an inner sleeve 104 which is fitted within the outer sleeve 114 forming the bottom of this annular space. An opening 103 is provided in the tube 102 so that liquid in the annular space rising to the level of this opening will overflow into the interior of the tube, which communicates with a central passage 1.13 in the inner sleeve 104; the lower end of this passage is connected to the upper end ofthe propellant return pipe 105. The latter is continued downwardly in juxtaposition to flue 52, being connected through a trap 106- to the lower part of the boiler 1. The arrangement of this return pipe in heat transfer relation to the flue permits the warming of the contained column of propellant which balances the boiler pressure, thus avoiding unnecessary thermal losses.

The outer surface of the inner sleeve 104 of the measuring factor 100 is provided with a helical groove 108 which'may resemble a screw thread, the upper end of this groove communicating with the annular space above the sleeve 104 and being ada ted to receive propellant from the same. elical passage 108 extends downwardly to a notch or groove 111 at the bottom of the sleeve 114, this notch communicating with a helical passage 112 disposed about the outer sleeve 114. The upper end of this helical passage communicates with an annular chamber 115 that is adapted to ventliquid into a pipe 116 extending to the purger. It is thus evident that the groove 108 in member 104 cooperates with the inner surface of the outer sleeve 114 to provide a long downwardly directed spiral passage which in turn is connected' through the notch 111 to the lower end of the groove 112 that cooperates with the inner surface of the casing 101 in providing a similar'passage that is connecte to chamber 115 and thus to the duct 116. This arrangement I permits a portion of the fluid passing into the space above the sleeve 104 to pass through the spiral passages and-thence to the duct 116. Due to the lengths and restricted sizes of these passages, they afford a comparative- 1y high resistance to the flow of the fluid so that a restricted quality only of the same may pass to the pipe 116, and so that the liquid piles up about the tube 102 and rises to the level of the opening 103. It is thus evident that the liquid in the spiral passages may thus be subjected to a definitely determined liquid head so that the quantity of liquid passing into pipe 16 quickly rises to its maximum height and is automatically maintained at that pointi despite wide Variations in the amount of liquid received by the factor 100.

Pipe 116 is also connected to the purger, which may include an entraining chamber 125, Fig. 15. A suitable pressure equalizing pipe 118 may be connected to the upper part of casing 101 to the chamber 125. The purger receives liquid propellant from the factor 100 and non-condensable gases through pipe 118 that is connected to the pipe 126 that extends to the gas collecting chamber 127. The latter is connected by pipes 129 and 129 to portions of the condenser 30 toward which the non-condensing gases are swept during normal operation of the device, i. e. the headers 36 and 40, while the connection between chamber 127 and the condenser are arranged so that refrigerant vapor passing into the latter upon condensing will flow back to the condenser.

Preferably the upper end of a duct 132 projects upwardly into the chamber 125, a suitable opening 133 in the side of this duct normally being adapted to receive the propellant. A suitable cylindrical screen 137 may be arranged within the chamber 125 about the duct 132 and a perforated disk 138 may be disposed in this foraminous cylinder above the pipe 132. Thus the entrance of foreign particles of appreciable size into the duct 132 is prevented. The lower end of the lat ter is connected toa downwardly extending tube 140 which has a restricted diameter and is therefore adapted to permit'the propellant to flow down the same in successive Iobules entraining bodies of non-condensa 1e gas therebetween. The lower end of tube 140 p is connected to a standpipe 145, the upper end of which may be exposed to any suitable gas receiving reglon such as the atmosphere. A pipe 146 extends upwardly from the lower end 'of the standpipe to an inclined connec-,

tion 147 that joins a downwardly extending by-pass duct 148 from the chamber 120 to the condenser 30. Preferably the duct 148 is connected to the header 36 of the condenser, i. e., the lower portion of the same. I

Ordinarily it is desirable to operate a system of this character at sub-atmospheric pressure. Accordingly it is desirable to make the system substantially fluid tight. In practice it has been found diflicult, however, toprovide a system of this character which. will be entirely free from minute leaks. Furthermore, certain gases may have been absorbed in the walls of the system itself and nance of comparatively low pressures by providing the purging means to exhaust a certain quantity of non-condensable gases as long as the system is operating. Thus the capacity of the purger may be sodetermined that it will take care of the maximum amount of non-condensable gases that are likely to occur in the s stem. Especially when a smaller quantity 0 gases find their way into the system, the purger will also exhaust refrigerant vapor as well as, non-condensable gases. However, the capacity of this purger may be so determined that it will operate satisfactorily and yet cause the exhaustion of no more than a small proportion of the contained refrigerant durmg a period of years. Ordinarily liquid from pipe 116 entrains the vapors or gases in the tube 140, the gases rising through the liquid in the standpipe 145 thus being exhausted to the atmosphere. The atmospheric pressureupon the liquid in the standpipe is suflicient to balance the internal pressures to which this portion of the system is'subjected and accordingly the upper end of pipe 146 receives the propellant from the lower end of the standpipe and vents the same through pipe 148 to the condenser. As previously indicated, the lower portion of this condenser is connected to the pipe 60 in which the liquid refrigerant is entrained between bodies of the falling propellant. The propellant passes from this portion of the system back-to the main propellant collecting pipe 50, whence it is returned to the main propellant circuit.

In order to prevent the accidental occurrence of excessive pressures within the boiler, for example, should the nozzles 9 and 9 become clogged, a safety pipe 240 connects the boiler with the pipe 99 through which propellant is supplied to the measuring factor. Normally the pipe 240 contains a column of ropellant of suitable height to balancethe boiler pressure. Under excessive boiler pressure, however, propellent vapor will be forced through pipe 240, thus preventing the occurrence of excessive pressure within the boiler. This vapor may be forced through the trap 98 and duct 96 to the refrigerant condenser, the full capacity of which is thus available to effect the condensation of the propellant under such abnormal conditions. Obviously a portion of this vapor will pass into the measuring factor 100 and return to the boiler in the normal manner.

In the'operation of a system of the character described herein, heat is supplied to the firebox 2, thus being efiectivein vaporizing the propellant in boiler 1 and causing the same to rise through ducts 6 to. aspirator nozzles 9 and 9. Refrigerant vapor'is drawn from the surface of the liquid in receptacle 12,

passing through pipe 11 to the mixing chamber 10 where it is entrained. in-the stream of propellant passing out of the nozzle 9. The mixed vapors flow into the funnel 15 where the propellant gives up its energy in pumping the refrigerant vapor. Since the propellant preferably is chosen to have a condensation point much higher than that of the refrigerant, substantially all of the propellant is condensed by thetime'that it reaches the lower end of the funnel 15, the cooling fins 16 aiding this effect. The condensed propellant is received by the drains 21 and 22 and passes from the same tothe propellant collectingduct 50. The refrigerant passes through the pipe 20, in which somecooling and consequent reduction in the volume of the refrigerant may take place, to the second stage mixing chamber l0 where the propellent vapor from the nozzle 9 is effective in further umping the refrigerant. The drains 21 and 22 collect the condensed propellant from the second stage pumping means, directing the same tdthe collecting pipe 50 The refrigerant vapor, wh ch has been compressed, rises through pipe-.26 to the condenser 30, which has suflicient capacity to effect the condensation of the refrigera t at the prevailingv pressure conditions. hus the liquefied refrigerant tends to flow to the lower part of the condenser, i. e., the header '36, from which the condensed refrigerant flows to the pipe 60. Since the duct 148 supplies liquid propellant to the header 36, the liquid refrigerant is entrained between globules of the heavy propellant in the pipe 60 which is of restricted diameter, this propellant imposes a fairly heavy liquid .head upon the trap 61. The propellant tends to flow to the lower portion of this trap and the lighter refrigerant rises through pipe 63 to chamber 65. l y

The major portion of the refrigerant from chamber 65 flows downwardly through pipe 66 to its connection 70 with the trap 7 3, while some of therefrigerant is supplied to the.

secondary vaporizer and thus to pipe'90. The chamber 7 0- receives both propellant and refrigerant, the former passing to trap 73 and the refrigerant rising through pipe 72 and being returned from the upper'end of the latter through pipe 220 and chamber 223 to the cooler 12. It is thus evident that the pressure imposedupon the liquid in pipe 60 plus the weight of that liquid is sufficient to alance the ressure of the column of the lighter liquid in pipe 72 plus the pressure thereabove ;-in other words, the comparatively high pressure within the refrigerantcondenser 30 plus the liquid head resulting from v the alternate bodies of propellant and refrigerant in pipe 60 is suflicient to balance the via the trap 61, connection 70, trap 73, and pipes 76 and 22 to the propellant collecting pipe 50. p

The portion of the refrigerant that is received by the secondary vaporizer 80 passes through the porous plug 85, being vaporized as it leaves the same due to the heat from the flue 52.and due to the different pressures at opposite sides of this plug. The refrigerant vapor from the vaporizer 80 passes through pipe 90 to the. duct 51, thus breaking off successive bodies of liquid propellant which have collected in a, column at the lower end of this pipe, which receives propellant from the collectlng pipe 50. Propellant is thus raised through pipe 51 to the leg 95 of trap 98, the

liquid propellant falling to the bottom of this trap and the refrigerant vapor passing hrough pipe 96 to condenser 30, where it rejoins the main refrigerant circuit.

Liquid propellant collecting in trap 98 flows from the same through connection 99 to the measuring factor 100. The spiral passages provided by this factor receive a portion of the propellant and are almost immediately effective in supplying the same to the entraining chamber 125 of the. purger through the duct 116. As further propellant is supplied to the measuring factor, it will pile up about the tube 102, Fig. 11, passing through the opening 103 and thus returning through pipe 105 to the boiler 1, it being evident that the boiler pressure may anced 'bya column of liquid propellant within .pipe 105, which extends upwardly to a level above the propellant condensers. I

Non-condensable gases which appear wlthin the system are swept into the refrigerant condenser 30, rising throughthe connections 129 and 129 to the collecting chamber 127, this chamberbeing arranged to receive a considerable body of non-condensable gases and being effective in aiding the condensation of any refrigerant vapor which may pass into the'same; the connections 129 and 129 are arranged to return suchliquefied refrigerant to condenser 30. The non-condensable gases, or, in the absence of the same, refrigerant vapor, pass through pipes 126 and 118 to the entraining chamber 125 where the propellant from themeasuring factor is separated into liquid globules or pistons which pass down be balbetween. Such gases or vapors tend to rise through the column of propellant in standpipe 145 and to be exhausted to the atmosphere. It is evident that the height ofstandpipe 145 is so determined'that the column of. propellant therein plus the atmospheric pressure thereabove ma be sufiicient to balance the pressure conditions within the parts of the system to which the stand ipe is connected and that the pipe has a su icient height to permit a variation in the height of the contained liquid column in accordance with variations in thebarometric and adjoining internal pressures. Due to the pressure thus imposed upon the lower end of the standpipe 145, propellant rises from the same through pipe 146 to the pipe 148, thus passing to the header 36 of the refrigerant condenser 30. The upper portion of pipe 148 also forms a bypass to permit the continued flow-of propellant to header 36 should the tube 140 become accidentally clogged. The propellant thus supplied to header 36 forms separate liquid pistons in pipe in the manner previous- 1 described, thus being effective in returning the condensed refrigerant to the cooler- It is thus evident that the measuring factor 100 is so arranged that upon starting of the operation of the system the propellant will first flow through the spiral passages and be supplied to the purger and the refrigerant lifter before it is directed to the return pipe 105. Accordingly the almost immediate op-- eration of the refrigerant lifter is ensured. Furthermore, the arrangement of the chamber and connecting ducts is such that refrigerant vapor will be supplied to the duct 90 and thus to the propellant lifter almost immediately after the system is started.

The safety pipe 240 is elfective in avoiding any possibility of the accidental occurrence of excess pressures within the system due to the development of an excesive back pressure in the funnels 15 and 15 or for any other analogous reason.

I claim:

1. Apparatus of the class described comprising a propellant circuit including a boiler and a propellant condenser, a refrigerant cir 'cuit including a cooler and a refrigerant condenser, said circuits having a common part in which vaporized propellant causes the circulation of refrigerant through 'ltS circuit,

means for receiving the condensed propellant from the propellant condenser andlifting the same to a region above the common part of said circuit, said means being connected to a measuring factor, a propellant return pipe connected to said measuring factor and having its lower end connected to the boiler, a purger employing the energy of the lifted pro ellant toefiect the exhaustion of noncon ensablesgajpe's from the system, said measuring factor being connected to said purger and arranged to shunt a portion of the propellant to said purger.

2. Apparatusvof the class described comprising a propellant circuit including a boiler and a propellant condenser, a refrigerant circuit including a cooler and a refrigerant condenser, said circuits having a common part in which vaporized propellant causes the circulation of refrigerant through its circuit, means for receiving the condensed propellant from the propellant condenser and lifting the same to a region above the common part of said circuit, said means being connected to a measuring factor, a propellant return pipe connected to said measuring factor and having its lowerend connected to the boiler, means for employing the potential energy of the lifted propellant to lift condensed refrigerant from the refrigerant condenser to the cooler, said measuring factor being arranged to direct a portion of the lifted propellant to said refrigerant lifting means,

3. Apparatus of the class described com-- nected to said means, a propellant return pipe connected to said measuring factor and having its lower end connected to the boiler, means for employing the potential energy of the lifted propellant to lift condensed refrigerant from the refrigerant condenser to the cooler, said measuring factor being arranged to direct a measured portion of the lifted propellant to said refrigerant lifting means in preference to directing said propellant to the return pipe.

4. Apparatus of the class described comprising a propellant circuit including a vaporizer and a propellant condenser, a refrigerant circuit including a cooler and refrigerant condenser, said circuits having a common part where the propellant causes the circulation of the refrigerant through its cirof the system is effective in entraining globules of propellant in the tube of restricted diameter.

6. A system of the class described comprising a propellant circuit, including a vaporizer and'a propellantcondenser, a refrigerant circuit including a cooler and a refrigerant condenser, said circuits having a part in common where vaporized propellant is effective in pumping refrigerant vapor from the cooler, said refrigerant being more volatile than the propellant, a resistance factor receiving a portion of the condensed propellant, a duct of restricted diameter in heat transfer relation to the boiler receiving said vapor, whereby the condensed refrigerant passing through the resistance factor is vaporized, an upwardly extending tube of restricted diameter arranged to receive this vaporized refrigerant and condensed propellant with the propellant divided into separate liquid globules that are lifted by the refrigerant vapor, and means to return the refrigerant vapor from the upper part of the tube to the refrigerant condenser, and means to separate the propellant therefrom and to direct the latter to a pressure balancing column which is connected to the boiler. 1

7. A system of the class described comprising a propellant circuit, including a vaporizer and a propellant condenser, a refrigerant circuit including a cooler and a refrigerant condenser, said circuits having apart in common where vaporized propellant is effective in pumping refrigerant vapor from the cooler, the refrigerant being relatively volatile, a resistance factor arranged to receive a portion of the condensed refrigerant, said factor being arranged in heat transfer relation to the heating factor for the boiler, a tube of restricted diameter connected tosaid resistance factor and extending upwardly to a portion of the system which normally has a low internal pressure, whereby the low pressure to which the outlet of the resistance factor is subjected and the heat applied to the same are effective in causing the vaporization of refrigerant to lift successive propellant globules through the tube of restricted diameter, a duct to direct the lifted propellant back to the boiler and a passage to return the vaporized refrigerant to the refrigerant condenser.

8. A- system of the class described comprisand a propellant condenser, a re rigerant circuit including a. cooler and a refrigerant condenser, said circuits having a part in common where vaporized propellant is effective in pumping refrigerant vapor from the cooler, a downwardly extendingtube of restricted diameter arranged to receive condensed refrigerant from the refrigerant condenser and separate globules of propellant between which the refrigerant is entrained, a downwardly extending duct connected to the lower end of the tube and receiving the propellant therefrom, and an upwardly extending duct, a resistance factor communicating with the latter and arranged to receive a portion of the refrigerant, and a downwardly extending duct arranged to receive the remainder of the refrigerant, the resistance factor being associated with heating means to effect the vaporization ofthe refrigerant supply thereto in order to cause the lifting of condensed propellant, the downwardly extending duct being connected to a return pipe to effect the return of the remaining refrigerant to the cooler.

9. A system of the class described comprising a propellant circuit, including a vaporizer and a propellant condenser, a refrigerating circuit including a cooler and a refrigerant condenser, said circuits having a part in common wherein vaporized propellant is effective in pumping refrigerant vapor from the cooler, a downwardly extending tube of restricted diameter arranged to receive condensed refrigerant from the refrigerant'condenser and separate globules of propellant between which the refrigerant is entrained, a downwardly extending duct connected to the lower end of the tube and receiving the propellant therefrom, and an upwardly extending duct receiving the refrigerant from the same, a resistance factor communicating with the latter and arranged to receive a portion of the refrigerant, said resistance factor being connected to a part of the system which is normally at low pressure, whereby refrigerant passing through the same may be vaporized, and a downwardly extending duct arranged to receive the remainder of the refrigerant, and a refrigerant return pipe arranged to receive refrigerant from said downwardly extending duct and to return'the same to the cooler.

10. A system of the class described comprising a propellant circuit including a vaporizer and a propellant condenser, a refrigerant circuit including a cooler and a refrigerant condenser, said circuits having a part in common where vaporized propellant is the cooler, a safety pipe connected to the ing a propellant circuit includin a vaporizer I cooler, said safety pipe normally containing a' column of liquid'propellant to balance the boiler pressure, the upper end of the pipe Q the vaporizer, means arranged to employ a being connected to a portion of the system which is in communication with the refrigerant condenser whereby upon the development of excessive pressures within the boiler, the propellant may be vaporized in the safety pipe and may pass to the refrigerant condenser. i

11. A system of the class described comprising a propellant circuit including a vaporizer and a propellant condenser, a refrigerant circuit including a cooler and a refrigerant condenser, said circuits having a part incommon where vaporized propellant is effective in pumping refrigerant vapor from the cooler, means to lift the condensed propellant above its condenser, a measuring actor arranged to receive the propellant thus lifted and to direct a portion of the same to the vaporizer, means arranged to employ aportion of the lifted propellant to exhaust non-condensable gases from the system, said measuring factor being arranged to divert a portion of the lifted propellant to said means.

12. A system of the class described comprising a propellant circuit including a vaporizer and a propellant condenser, a refrigerant circuit including a cooler and a refrigerant condenser, said circuits having a part in common where vaporized propellant is elfective in pumping refrigerant vapor from the cooler, means to lift the condensed propellant above its condenser, a measuring factor arranged to receive the propellant thus lifted and to direct a'portion of the same in the vaporizer, means arranged to employ a portion of the lifted propellant to exhaust non-condensable gases from the system, said measurin factor being arranged to divert a portion 0 the lifted propellant to said means, said measuring factor comprising a spiral duct portion of restricted cross-sectional size which affords an appreciable resistance to the flow of liquid, said passage being connected to the aforesaid means, and a downwardly extending duct connecting the measuring factor to the boiler, said passage and said duct both having inlet portions arranged to receive the liquid propellant.

13. A system of the class described comprising a propellant circuit including a vaporizer and a propellant condenser, a refrigerant circuit including a cooler and a refrigerant condenser, said circuits having a part in common where vaporized propellant is .effective in pumping refrigerant vapor from the cooler, means to lift the condensed propellant above its condenser, a measuring factor arranged to receive the propellant thus lifted and to direct a portion of the same to portion of the lifted propellant to exhaixst non-condensable gases from the system, said lant, the duct having its inlet portion ar-- ranged above that of the spiral passage whereby the liquid propellant may have a definite head to impose pressure upon the passage before passing downwardly through the duct.

14. A system of the class described comprising a propellant circuit including a vaporizer and a propellant condenser, a refrigerant circuit including a cooler and a refrigerant condenser, said circuits having a part in common where vaporized propellant is effective in pumping refrigerant vapor from the cooler, means to lift the condensed propellant above its condenser, a measuring, factor arranged to receive the propellant thus lifted and to direct a portion of the same to the vaporizer, means arranged to employ a portion of the lifted propellant to exhaust non-condensable gases from the system, said measuring factor being arranged to divert a portion of the lifted propellant to said means, a pressure equalizing duct connecting the measuring factor to said means and said equalizing duct being arranged above the portions of said factor and said means which normally contain liquid whereby the gaseous pressures in said portions of the systems may be equalized.

15. In' apparatus of the class described, means to divide the supply of liquid between two duct portions and to insure the supply 'of a definite quantity of liquid to one of said'portions before any of the liquid passes to the other of the same, said means including a receptacle, an elongate passage of restricted diameter arranged to receive liquid from the bottom of the receptacle, one duct portion communicating with the receptacle above the bottom of the same, said passage of restricted diameter being connected to the other of said duct portions whereby the liquid admitted to the receptacle will immediately pass into the passage of restricted diameter and thus to the corresponding duct portion and will also pass into the other duct portion after it has risen to the point of communication of the receptacle with the other duct portion.

16. In a system of the class described, a measuring factor comprising a chamber, a duct portion extending upwardly in said chamber and having an opening above the bottom of the chamber, an elongate spiral passage of restricted diameter communicating with the bottom of the chamber where by liquid will be preferentially supplied to 130 the spiral passage until it rises in the chamber to the height of said opening.

17. In a system of the class described, a measuring factor comprising a cylindrical chamber, a sleeve having a helical groove formed thereon engaging the inner wall of and an outlet duct connected to the upper,

end of the outer passage.

18. In a system of the class described, a measuring factor comprising a cylindrical chamber, a sleeve having a helical groove formed thereon engaging the inner wall of said chamber so that it cooperates therewith in providing an elongate helical passage, an inner sleeve fitting in the outer sleeve and having a helical groove cooperating with the outer sleeve in providing a helical passage, an outlet duct connected to the upper portion of said last lam-ed passage, a connection between said helical passages, the inner and outer sleeves being arranged to provide a chamber for supplying liquid to the outer endof the inner helical passage, and a central duct portion extending upwardly into said chamber and having an opening communicating with said chamber above the upper end of the inner sleeve whereby a definite liquid head may be imposed upon the spiral passages before liquid will pass through said opening into the duct portion. Signed by me at Cambridge, Mass, this 4th day of November, 1929.

EASTMAN A. WEAVER. 

